Transmissions are by their very nature very complex apparatus. Replacement of major transmission subassemblies as part of repair operations or for the purpose of achieving different operational qualities is a difficult and time-consuming task. Major changes in a transmission for the latter purpose are rarely undertaken.
Creepers are helpful in certain very slow operations extending over a protracted period of time, such as the planting of seedlings. If a creeper is needed, it would usually have been an included option at the time the tractor is purchased. But tractors usually do not need to be equipped with creeper drives and do not include them.
There are occasions when a farmer who did not anticipate the need for a creeper will need to utilize his tractor for something requiring a very slow drive speed and wish his tractor had been equipped with a creeper. To make a change in the transmission is at best very difficult, time-consuming and expensive. Rather than undergoing expensive transmission rebuilding procedures or acquiring a new tractor, it would be very desirable to have a simple method for the purpose of revising a tractor transmission to include a creeper.